Show HN: Toolflow – Fixing AI Tool Calling Context Bloat

AI-Native Tool Calling Framework — Build intelligent agents that interact with tools via natural language, with minimal context bloat and full developer control.

Modern AI agents rely heavily on tool calling to fetch data or perform actions. But in practice:

• 🔥 Tool responses are too large, flooding the LLM context window.
• 🤯 Developers have no control over what part of the API response is used.
• 🧩 Mapping tools to agents is hard across different APIs and use cases.
• 🐘 Most frameworks assume monoliths — no modularity or control for devs building production systems.

"Fetching Gmail emails returns hundreds of fields. I just need subject, from, and snippet!"
– Every AI dev, ever

Toolflow is an AI-native middleware layer to connect APIs and tools to LLM agents, with:

• 🔍 Minimal context payloads: Filter what actually goes to the LLM.
• 🛠️ Composable tool registry: Define tools + actions as modular objects.
• ⚙️ Custom modes:
  • Light – Send only minimal fields
  • Full – Send entire response
  • AI Filter – Auto-trim fields based on relevance
  • Custom – Dev chooses fields at runtime
• 📦 Plug-n-play TypeScript packages for runtime, registry, and types.
• ⚡ Works with existing frameworks (Langchain, Flowise, AutoGen, etc.)

+-------------+ +----------------+ | Tool Config | | Executor | | (Metadata) | | (Calls API) | +-------------+ +----------------+ | | +-----------+-----------+ v +----------------------+ | External API (Gmail) | +----------------------+

Filtered response :

{ "data": { "messages": [ { "from": "Dheeraj Kumar", "subject": "Repo check", "snippet": "Hi Dheeraj, Does this repo makes sense ?", "date": "Tue, 17 Jun 2025 12:01:00 +0200" } ], "nextPageToken": "16428802254119354251", "resultSizeEstimate": 201 }, "error": null, "successfull": true, "successful": true, "logId": "log_3XvoX1kpxPM6" }

git clone https://github.com/dksingh1997/Toolflow.git cd Toolflow npm install npm run dev

apps/ └── web/ → Next.js frontend + API handlers

packages/ ├── types/ → Shared TypeScript types ├── registry/ → Tool definitions └── runtime/ → Core execution logic